Power toothbrush or the like with orbital brush action

ABSTRACT

The disclosure relates to a power toothbrush or the like characterized particularly by the fact that the brush element is driven in an orbital path, as distinguished from a more conventional angularly reciprocating motion. To particular advantage, the power driven brush may be motivated by a water powered nutating action motor mounted in the handle of the unit, although alternative arrangements, including conventional electric motor units, may be used to power the device. In the preferred appliance, an orbital output motion of a nutating drive motor is converted to rotary motion, and this in turn is converted back to an orbital motion in the brush or working element. In other forms of the device, the orbital output of the nutating motor is imparted directly to the working element. The latter arrangement has advantages of greater simplicity, while the former arrangement has advantages of greater compactness.

This is a division of application Ser. No. 70,689, filed 8/29/79, nowU.S. Pat. No. 4,276,672, which in turn is a division of application Ser.No. 848,807 filed 11/7/77, now U.S. Pat. No. 4,175,299.

BACKGROUND AND SUMMARY OF THE INVENTION

Power toothbrushes are well known and widely used home appliances.Typically, these devices are electrically driven, utilizing either arotary electric drive or a form of reciprocating, vibratory drive. Theworking element (i.e., the brush) typically is driven a reciprocateeither linearly or through a limited rotary motion. In either case, theworking element executes a back and forth motion over the teeth andgums. In accordance with one aspect of the present invention, a new andimproved powered toothbrush appliance is provided in which the workingelement is arranged to execute an orbital motion, such that the primaryworking stroke of the brush over the teeth and/or gums is effectivelylargely unidirectional. During the return motion of the brush, itsorbital path tends to retract it away from the teeth and gums, or atleast lessen the pressure during the return stroke. This motion providesa brush stroke which approximates the theoretical ideal, in that theprimary working stroke can be unidirectional, from the base of the gums,either upward or downward as the case may be, toward the tips of theteeth. The motion is reversable, of course, so that the working strokemay be in an upward direction for the lower teeth and in a downwarddirection for the upper teeth.

In one of the most advantageous forms of the invention, motive power isprovided by a water driven nutating motor having an orbitally movingoutput element. Pursuant to one aspect of the invention, in order tominimize the overall length of the appliance, from the base of thehandle to the tip of the brush, the orbital motion of the nutating motoris converted to a rotary motion through an intermediate drive member,and this drive member in turn imparts the desired orbital motion to theworking element or brush.

Where somewhat greater overall length of the appliance is notobjectionable, the orbital output of the nutating motor may be imparteddirectly to the working element. The latter arrangement is characterizedby greater mechanical simplicity, but requires somewhat greater lengthin order to achieve an orbital path of proper dimensions at the tip ofthe working element.

In accordance with a still further aspect of the invention, a poweredtoothbrush appliance is provided, in which the working element is causedto execute the desired reversable orbital path, being driven, however,by a conventional rotary electric motor, mounted in the handle of theappliance. This has the advantage of extreme simplicity.

In any of the water-powered versions of the new appliance, provision maybe made for controllably diverting at least a portion of the motivefluid--water--into the shank of the brush, to be discharged into thebristle area at the head of the brush. This provides a highly efficientmoistening and rinsing action, so that brushing with dentifrice andrinsing may be completed in a single, continuous operation, withoutinterruption for obtaining rinse water from another source.

For a more complete understanding of the above and other features andadvantages of the invention, reference should be made to the followingdetailed description of preferred embodiments of the invention, and tothe accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal cross sectional view of a water driventoothbrush appliance forming a preferred embodiment of the invention.

FIGS. 2 and 3 are fragmentary cross sectional views as taken generallyon lines 2--2, 3--3 respectively of FIG. 1.

FIG. 4 is vertical cross sectional view illustrating a reversing valvearrangement advantageously incorporated in the appliance of FIG. 1.

FIG. 5 is a second vertical cross sectional view of the reversing valveof FIG. 4, taken at right angles to the view of FIG. 4.

FIG. 6 is a simplified cross sectional view of a manual control valvearrangement, providing a controlled discharge of water through the brushhead of the appliance.

FIG. 7 is a longitudinal cross sectional view of a modified form ofbrush mounting element arranged for advantageous incorporation in theappliance of FIG. 1.

FIG. 8 is a simplified perspective representation of a water drivenbrush appliance according to the invention, connected to a faucet outletor the like through an attachment fitting provided for that purpose.

FIg. 9 is a longitudinal cross sectional view through the toothbrushappliance of FIG. 8, illustrating internal details of construction.

FIG. 10 is a cross sectional view as taken generally along line 10--10of FIG. 9.

FIG. 11 is a longitudinal cross sectional view of a further modifiedform of the toothbrush appliance of the invention.

FIGS. 12 and 13 are enlarged, fragmentary illustrations of a universaljoint arrangement incorporated in the appliance of FIG. 11.

FIG. 14 is an enlarged, fragmentary cross sectional view illustratingthe manner of mounting the brush holding element in the appliance ofFIG. 11.

FIG. 15 is a longitudinal cross sectional view of a further modifiedform of a new appliance, in which the brush element is driven in anorbital path by an electric motor drive.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Referring now to the drawings, and initially to FIGS. 1-6 thereof, thereference numeral 20 designates generally the body or handle portion ofa power toothbrush appliance. Desirably, the body portion, as well asmost of the internal and working parts of the device are comprised ofprecision moldings of suitable structural plastic material joined byadhesive or mechanical means, as deemed appropriate to thecircumstances. In the device of FIG. 1, a nutating action drive motor 21is provided, which consists of upper and lower motor casings 22, 23, theexterior surfaces of which may form part of the body 20. Internally, themotor casing 21 mounts a so-called Saturn disc 24, from which extends anoutput rod 25. The nutating action motor does not, in and of itself,form an invention of the present application, and reference may be madeto our copending application Ser. No. 827,625, filed Aug. 25, 1977, andalso in our copending application Ser. No. 848,806, filed Nov. 7, 1977,U.S. Pat. No. 4,175,359, further details relating to specifics of thenutating action motor. For the purpose of this disclosure, it issufficient to note that motive fluid, in this case water, enters themotor chamber 26 on one side of a vertical divider plate (notspecifically shown) and flows circumferentially around the chamber,exiting at a discharge port on the opposite side of the dividing plate.In thus traveling around the chamber 26, the motive fluid progressivelydisplaces the Saturn disc, causing it to execute a progressive wobblingmotion, without rotation. The output rod 25 is thus caused to execute anorbital motion within the chamber 27. The direction of orbital movementof the upward rod 25 may be reversed by reversing the direction of fluidflow through the motor chamber 26, and this is accomplished in theillustrated device by means of a reversing valve 28 mounted in the lowerpart of the housing 20, to be described in further detail.

Journaled in an intermediate portion 29 of the appliance body is arotary transmission element 30. To simplify assembly, the transmissionelement 30 consists of a lower shaft section 31 which extends throughand is rotatably supported by a cylindrical bearing passage 32 in thehousing. The shaft section 31 has an enlarged head portion 33, which isreceived in the chamber 27 and, among other functions, acts as a thrustbearing.

The upper end portion of the shaft section 31 is recessed for thereception of an upper shaft section 34. The upper and lower shaftsections 31, 34 are drivingly connected, either by a splined associationtherebetween, or by being bonded together during the initial assemblyoperation. The enlarged head 35 of the upper shaft element seats againsta thrust bearing surface 36 to provide rotary support for the uppershaft element.

As reflected in FIG. 1, the upper portion 35 of the upper shaft section34 is provided with a radially offset, angularly disposed recess 37 forthe reception of a wobble shaft 38, the shaft having a cylindricalextension 39 which is received within the recess 37, for relativerotation of the rotary transmission element 30 in relation to the wobbleshaft. The shaft 38 has a shoulder 40 arranged for cooperation with theupper end of the rotary shaft head 35 to provide thrust support for thewobble shaft.

As shown particularly in FIGS. 1 and 3, the upper end of the appliancehousing 20 is formed by a cap 41 of generally frusto-conicalconfiguration. The upper end of the cap 41 is provided with anoncircular opening 42 which receives with minimum but slight clearancea similarly configured neck portion 43 of the wobble shaft. Directlyunder the neck portion 43, the wobble shaft is again of circular crosssection and receives an O-ring 44. The O-ring is captured between aninternal shoulder 45 on the cap 41 and an upwardly facing shoulder 46formed on the wobble shaft. The O-ring 44 thus forms a resilientuniversal pivot mounting for the wobble shaft, permitting an orbitalwobble motion of the shaft upon rotation of the rotary shaft element 31.

The upper extremity of the wobble shaft 38 is provided with a recess 47located just below its upwardly tapered extremity 48 (see FIG. 7). Thisupper end extremity is adapted to releasably retain a brush head 49having a bristle section 50 at its outer end. The brush head 49 has anenlarged lower end 51, provided with an internal socket complementary tothe upper end extremity of the wobble shaft. Both the socket and the end48 of the wobble shaft are of noncircular cross section so that thebrush head does not rotate with respect to the wobble shaft. An O-ring52 is received in the socket of the brush head, for releasableengagement with the recess 47 in the wobble shaft, to lock the brushhead to the shaft in a firm yet releasable manner.

As reflected in FIG. 1, the appliance body 20 is connected at its lowerend to a length of Siamese tubing 53, having individual pressure andexhaust channels therein. The tubing is connected to the reversing valve28, to be described in further detail, and the reversing valve isconnected in turn to the motor chamber 26, on opposite sides of thedividing plate. Depending on the setting of the reversing valve, thesaturn disc 24 of the nutating motor will be motivated to move itsoutput rod 25 either clockwise or counterclockwise through an orbitalpath. The upper portion of the motor output rod 25 is rotatably receivedwithin a bearing pad 54 of a plunger 55 slideably received within a lug56 provided on the shaft head 33. A coil spring 57 constantly urges theplunger 55 toward the operating rod 25 of the nutating disc, at alltimes maintaining the disc tilted or canted to the maximum extent. Forfurther details of this and other yieldable canting arrangements for theSatura disc, reference may be made to our copending applications Ser.No. 848,806 and Ser. No. 827,625. A significant advantage to be derivedfrom this arrangement is that the disc is at all times maintainedproperly and fully canted, taking into consideration variations inoriginal manufacturing tolerances, wear from sustained use, and likeconditions. Moreover, should for some reason the mechanism become jammedor stalled, the spring 57 can yield against the pressure of the motivefluid within the motor chamber, allowing the motor to stall and bypassfluid without damaging the unit.

When the disc 24 is motivated through its orbital motions, the operatingrod 25 serves to rotate the rotary shaft assembly 30 abouts its axis.The wobble shaft 38, being fixed against rotation by the housing cap 41,does not rotate with the upper portion 35 of the rotary shaft. However,because of the offset, angular orientation of the socket 37, the lowerend 39 of the wobble shaft is caused to move through an orbital path.This in turn causes the outer end of the brush head 49 to move throughan orbital path, as the wobble shaft 38 pivots universally within theO-ring 44.

In accordance with one aspect of the invention, one side of the watersystem, most advantageously the exhaust side, is connected throughinternal passages in the appliance housing to the chamber 58 surroundingthe lower end of the wobble shaft 38. Passages 59 are provided withinthe wobble shaft, which connect with a passage 60 in the brush head. Thepassage 60 discharges into the bristle section 50 of the brush head, asindicated in the drawing.

In conjunction with the above described system of water passages, meansare provided for controllably introducing back pressure in the dischargeor exhaust side of the Siamese tubing 53. When such back pressure isprovided, at least some of the exhaust water being dischargedcontinuously from the nutating motor 21 is forced through the passages59, 60 and is discharged into the bristle area 50 to provide a desirablerinsing action.

An advantageous form of back pressure control arrangement is illustratedin FIG. 6. A valve housing 61 is connected into the exhaust portion 62,63 of the Siamese tubing. At a position convenient for manualmanipulation by the operator. Alternatively, the control may be locatedon the appliance itself. In either instance, provision is made in thevalve body for relatively unrestricted flow of the exhaust water,through a control passage 64 from section 62 of the exhaust tubing tosection 63 thereof. The valve passage 64 cooperates with a valve member65 mounted on or formed integrally with a manually deformable diaphragm66 positioned for convenient engagement by the operator's thumb orfinger. When the diaphragm 66 is depressed, the valve element 65 closesthe passage 64 to restrict the flow of exhaust liquid through the outlettubing. Desirably, the tubing section 62, 63 are joined by a passage 67of limited cross section, such that when the valve 65 fully closes thepassage 64, a minimum flow of exhaust flow is still permitted throughthe Siamese tubing, with the remainder being discharged through thebristle area 50 for rinsing purposes.

With reference now particularly to FIGS. 4 and 5, an advantageous formof reversing valve for use in connection with the appliance of FIG. 1comprises a molded plastic body, preferably contoured so as to form anintegral part of the appliance body or handle. The body 70 of the valveincludes inlet and exhaust ports 71, 72 respectively at its lower end.At the upper end, there are provided ports 73, 74, which are alternatelypressure or exhaust, depending on the setting of the valve. The lowerports 71, 72 are connected to the respective sides of the Siamese tubing53, while the upper ports 73, 74 are connected to the nutating motor 21,on opposite sides of its dividing plate.

Within the valve body 70 there are formed internal chambers 75, 76connected by passages 77, 78 to the respective inlet and outlet port 71,72. Accordingly, the chamber 75 may be considered a pressure chamber,while the chamber 76 may be considered an exhaust chamber. Each of thechambers 75, 76 has opposed outlet ports 79, 80 in the case of thechamber 75, and 81, 82 in the case of the chamber 76. The ports 79, 81,on one side, connect with a common passage 83 leading to the port 73connected to the nutating motor. Likewise, the chamber ports 80, 82 onthe opposite side connect with a common passage 84, leading to the port74.

Mounted rotatably within the valve plug 70 is a control shaft 85, anextension 86 of which projects out from the valve plug and mounts anoperating wheel 87 (FIG. 2). The inner portion 85 of the operating shaftcarries a cross bar 88, opposite ends of which project into therespective pressure and exhaust chambers 75, 76. At its ends, the crossbar 88 is enlarged and rounded for the reception of resilient valvespheres 89, 90. The geometrical arrangement of the cross bar and valvespheres 89, 90 is such that, when the shaft 85 is rotated in onedirection to a limit position, the valve spheres will move into closingposition with respect to upper and lower ports on opposite sides. Thus,in the positions shown in FIG. 5, the lower sphere 89 closes the port 80leading into the common passage 84, while opening the pressure chamber75 to the common passage 83, through the opposite port 79. The uppersphere 90 opens the port 82, connecting the common passage 84 to theexhaust chamber, while closing off the passage 83 thereto. Thus, whenthe valve member is in the position illustrated in FIG. 5, pressurefluid is supplied to the nutating motor through the valve outlet port73, while the exhaust fluid from the motor returns through port 74. Whenthe valve element is moved to its other position, pressure fluid issupplied to the motor to the valve port 74, reversing the direction ofthe motor.

Appropriate means may be provided for rendering the movable valveelements, including the cross bar 88 and shaft 85, self-holding ineither operative position. This may be accomplished in various ways, asby mechanical detent means or by slightly unbalancing the valve element.For example, the exhaust chamber ports 81, 82 may be made slightlysmaller than the pressure chamber ports 79, 80, so that forces tendingto keep the valve closed in any position are somewhat greater than thosetending to open it. Similar results can be achieved by providing forasymmetry in the extension of the cross bar element 88, to be slightlylonger on the side entering the pressure chamber than on the sideentering the exhaust chamber. In many cases, the slight pressure drop inthe flow of fluid along the common passages 83 or 84 from the pressurechamber provides a sufficient pressure differential to impartself-holding characteristics to the valve.

For convenience, provision is made for manipulation of the reversingvalve 28 by means of a control ring 91 (FIG. 1) which is mounted on theappliance body 20, just below the cap 41, in a position to be easilyengaged by the thumb of an operator holding the main body of theappliance. The ring, which is arranged for limited rotation, has aninternal recess 92 engaging the upper end 93 of a pivoted control level94 (FIG. 2). The lever 94 has a cylindrical boss 95 in its centerportion, which is received in a corresponding cylindrical recess 96 inthe appliance body. The entire lever 94 is contained within a narrowvertical recess in the handle body, which accommodates a limitedpivoting movement, typically a total swing of about 3°. At the lower endextremity of the control lever 94, there is a lug 97 which is receivedin a recess 98 in the control wheel 87 which is fixed to the valveoperating shaft. The geometric relationship of the parts is such that,upon relatively small (e.g., 3°) movement of the control lever 94, thecontrol wheel 87 will have a somewhat more magnified motion of, say,15°, sufficient to switch the reversing valve from one operativeposition to another. The arrangement provides for reversing of theorbital movement of the brush head 49, by a convenient, side-to-sidemotion of the thumb of an operator holding the appliance.

FIG. 7 illustrates a modified form of wobble shaft which may be used toadvantage in the appliance of FIG. 1. In the modified form of shaft,identified generally by the reference numeral 38a, internal waterpassages 101, for the discharge of water into the brush head, arecontrollably blocked by a spring loaded check valve 102. This provides amore positive control over the discharge of water through the brushhead, since a higher level of back pressure in the discharge line mustexist before the flow of water commences through the check valve 102.

It is also possible, of course, to divert inlet pressure up to the brushhead through a controllable on-off valve, but it is usually moreconvenient to divert water from the exhaust side of the nutating motorfor this purpose.

Referring now to FIGS. 8-10, there is illustrated a modified form of theinvention, in which the orbital output motion of a nutating motor isimparted directly to a brush head-supporting wobble shaft in atoothbrush appliance. Thus, in FIG. 9, the reference numeral 110designates generally the lower housing of the appliance, which forms acasing for a nutating drive motor. The housing 110 defines a chamber 111supporting and containing a Saturn disc 112 of the nutating motor. Thegeneral principles of operation of the motor itself are similar to thoseof the motor described in connection with FIGS. 1-8, with certainexceptions to be noted. The upper wall 113 of the motor housing has anopening through which extends an operating rod 114 which, in this case,is of tubular cross section. The operating rod 114 carries a sphericalelement 115 at its outer end extremity.

An upper housing portion 116, which forms a hand grip, extends from thelower housing 110 and houses an elongated, tubular wobble shaft 117. Thewobble shaft 117 has a bearing element 118 at its outer end, whichcooperates with a correspondingly shaped bearing socket 119 formed inthe end of the upper housing 116. The arrangement of the bearing 118 andbearing socket 119 is such as to accommodate limited universal pivotingmovement of the wobble shaft 117, while preventing rotation thereof.

The outer end of the wobble shaft 117 is recessed to non-rotatablyreceive the shank 120 of a removable brush head 121 provided withbristles 122 of a conventional character.

Pursuant to the invention, the inner end 123 of the wobble shaft isprovided with a cylindrical recess 124 for the slideable reception of abearing plunger 125. The outer end of the bearing plunger has aspherical socket for the reception of the end of the motor operating rod114, and the plunger is at all times yieldably urged toward theoperating rod by a small spring 126 positioned in the upper end of therecess 124.

In the assembled appliance, the bearing plunger 125 constantly urges theoperating rod 114, and thus the Saturn disc 112 of the nutating motor,to a position of maximum tilt or cant within the chamber 111. Thisassures optimum positioning of the disc 112, while at the same timeaccommodating minor variations in dimensions of the parts throughmanufacturing tolerances, wear, etc. As in the case of the previouslydescribed embodiment, the yieldable canting of the Saturn disc providesfor automatic pressure relief, in the event the mechanism becomes jammedor stalled, inasmuch as the water can tilt the disc slightly toward aneutral position, against the action of the spring 126, to permit waterflow through the motor housing without further progressive displacementof the disc.

In the arrangement of FIGS. 8-10, a suitable removable attachment 127may be provided for connection of a Siamese tubing 128 to a conventionalfaucet outlet 129. The attachment 127 fastens to the end of the faucetand, when the water is turned on, diverts pressure water through one ofthe passages 130 of the Siamese tubing. Return water is directed throughthe other passage 131 and is ultimately discharged through the bottom ofthe attachment 127.

As reflected in FIG. 10, the separate passages of the Siamese tubing areappropriately connected such that one of the passages terminates at aninlet opening 132 in the motor chamber 111, while the outer passageterminates in an exhaust port 133. In a well known manner, fluidentering the inlet port 132 travels circumferentially around the motorchamber, progressively tilting the disc 112, which is supported forlimited universal movement by a spherical bearing 134. The resultingorbital output movement of the operating rod 114 is transmitted directlyto the wobble shaft 117 and brush head 121.

In order to reverse the orbital motion of the brush head 121, it isnecessary to reverse the flow of flow through the motor chamber 111. Inthe embodiment illustrated in FIGS. 8-10, this may be accomplished by areversing valve 135 forming part of the faucet attachment 127. In theembodiment of FIGS. 8-10, provisions are made for periodic discharge ofrinse water through the brush head 121 during a portion of each cycle ofthe nutating motor. This is achieved by providing a small duct 136leading from each of the passages 130, 131 of the Siamese tubing 128 andterminating at the spherical bearing seat 137 for a Saturn disc 112. Thelocation of the ducts 136 is such that, during portions of the orbitalcycle of the lower end of the tubular operating rod 114, the interior ofthe operating rod is aligned with the ducts 136. When that alignmentoccurs with the duct which is under pressure, water momentarily flowsthrough the operating rod and into a passage 138 of the bearing plunger125. The water then flows through an internal passage 138 in the wobbleshaft and through a like passage 139 in the brush head, to be dischargedin the bristle area. With the described arrangement, a pulsating flow ofrinse water is provided through the brush head during operation of thedevice. If desired, of course, the inlet source to the passages 136 maybe selectively valved, such that the pulsating rinse water supply may beturned on or off as desired by the user.

The embodiment of FIGS. 11-14 is similar in basic function to that ofFIGS. 8-10, in that the orbital output of a nutating motor istransmitted directly to a brush head-supporting wobble shaft. A mainhandle-forming casing 140 is connected to a Siamese tubing 141 leadingfrom an appropriate source of water under pressure and a reversingvalve. Individual passages 142, 143 of the tubing lead, by passages notillustrated, to the interior of the motor chamber 144, on opposite sidesof its divider plate. A Saturn disc 145, constituting the movableelement of the nutating motor, has an output element 146, on which ismounted a socket 147 forming a portion of a universal drive joint. Atubular wobble shaft 148 is provided at its lower end with a similarsocket portion 149 forming another part of the universal joint drive.The two socket portions 147, 149 mutually engage a spherical bearing 150provided with pairs of radially extending rods 151. The arrangement issuch that the operating element 146 of the nutuating motor isnon-rotatably connected to the wobble shaft 148. By this means, thewobble shaft may be maintained against rotation by the Saturn disc 145(or vice versa). Thus, the Saturn disc 145 normally is prevented fromrotating by means of the divider plate (see item 152, FIG. 10), which isstraddled by edges of the plate forming the Saturn disc. Reference maybe made to edges 153, FIG. 10, which illustrates a correspondingconstruction in the motor in the embodiment of FIGS. 8-10. By thusnon-rotatably joining the output element 146 in the wobble shaft 148,the desired orbital movement of the wobble shaft may be achieved whilethe shaft is retained against rotation. In addition, it may be desirableto provide means, such as a flexible boot 154, by means of which theupper end of the wobble shaft 148 is secured to the upper end of theappliance housing 140. The flexible boot 154 permits the intendedorbital wobbling movement of the shaft 148 while preventing rotationthereof.

Within the housing 140, the wobble shaft 148 is provided with a flange155. A spring 156 is seated on the flange 155 and also against aninternal shoulder 157 in the housing such that the spring urges theentire wobble shaft 148 down into the housing 140, toward the outputelement 146 of the nutating motor. The spring 156 thus serves tonormally maintain the Saturn disc 145 fully canted, while providing forpressure relief in the event of stall or overload. The flexible boot 154provides for limited axial displacement of the wobble shaft 148 toaccommodate such relief, as will be understood.

As in the case of the embodiment of FIGS. 8-10, the wobble shaft 148internally receives the shank 158 of a replaceable brush head 159. Alsoas in the case of the embodiment of FIGS. 8-10, internal passages 160,161 are provided in the brush head and wobble shaft for the supply ofrinse water for discharge in the bristle area of the brush. A passage162 through the spherical bearing of the Saturn disc, which periodicallycommunicates with passages 163, 164 in the motor housing, and with apassage 165 in the universal bearing sphere 150, provides for periodicpulsating discharge of water through the brush. The pulsating dischargemay, of course, be valved if desired. Likewise, the discharge of waterthrough the brush head, when valved on, may be made continuous, ifdesired, by appropriate recessing of the relatively movablepassage-forming parts, so that constant, rather than periodic,communication is provided during movement of the Saturn disc.

As will be understood, a two-axis universal joint mechanism, such asutilized in the device of FIGS. 11-14 does not have "constant speed"characteristics under rotation, when the drive elements are disposed atan angle. Similar characteristics are evident in the mechanism of theinvention, even though the parts do not rotate about their axis butmerely move through an orbital path. By properly orienting the universaljoint mechanism in relation to the bristles of the brush head, it ispossible to derive relatively increased power during the working strokeof the bristles and relatively increased speed during non-workingmotions.

In the modification illustrated in FIG. 15, an orbital motion toothbrushappliance is provided which is driven by a relatively conventional,rotary electric motor 160a controlled for reversable rotation by themanually operated reversing switch 161 in the base of the appliancehousing 162. At the upper end of the housing 162 there is provided ahousing cap 163a which, in the illustrated example, is constructed of aresilient material. The cap 163a supports for limited universal pivotingmovement a wobble shaft 164a. The outer end 165 of the wobble shaft isarranged to mount a removable brush head 166. As in the case of thepreviously described embodiments, the wobble shaft 164a is non-rotatablerelative to the housing 162, and the brush head 166 is non-rotatablerelative to the wobble shaft.

Pursuant to the invention, the output shaft 167 of the electric motorcarries a displacement arm 168 provided with a notch 169 in its outerend. The lower end 170 of the wobble shaft is received in this notch.Accordingly, when the motor shaft 167 is rotated, the lower end of thewobble shaft is driven through an orbital path as a function of theeffective radius and rotation of the displacement arm 168. This orbitalmotion of the wobble shaft is translated directly to the brush head 166to achieve the desired orbital motion of the bristles 171. Reversing ofthe orbital motion of the brush head is of course accomplished byreversal of motor rotation through the switdh 161a.

In any of its various forms, the power driven toothbrush of theinvention enables a highly advantageous orbital brush action to beachieved in a simple and effective way. The orbital action, with acapability of reversal of direction, approaches a theoretical idealmotion for cleaning of the teeth.

In all forms of the invention, the desired orbital output motion of abrush head is achieved by means of an orbitally driven wobble shaft,which is non-rotatably mounted in the appliance housing, for universalpivoting movement at a point adjacent the outer end of the housing. Thebrush head extends outward from this point and, in the area of thebristles, describes an orbital path whose diameter desirably is ofaround 5.5 mm. In all cases, however, in the region of the universalpivot point, the orbital path of the brush head approaches zero. Thus,in the area where the brush appliance enters the mouth, its motion isvery small, and the size of the housing can be very small. At the sametime, the orbital motion at the brush head proper is entirely adequatefor the purposes intended.

The embodiments of FIGS. 1-14 all make advantageous use of a novel formof water-driven nutating motor, which can utilize faucet water as apower source, with simple and convenient provisions for diverting someof that water through the brush head for rinsing purposes. In theembodiments of FIGS. 8-14, the orbital output of the nutating motor isimparted directly to the brush head-supporting wobble shaft, such thatthe orbital motion of the nutating motor is transmitted directly to thebrush head. In the modification of FIGS. 1-7, provisions are made forinitially converting the orbital motion of the nutating motor to purerotary motion, and then for re-converting that rotary motion back to anorbital motion of a brush head-supporting wobble shaft. The lastmentioned embodiment, while introducing an additional mechanical stage,has certain practical advantages with respect to reducing the overalllength of th appliance. In this respect, in a nutating motor ofappropriate size and power for the purpose intended, the output rod willhave a diameter of orbital movement of a given size. To convert thatorbital movement to a desired (e.g., 5.5 mm diameter) orbital movementof a brush head of convenient and standardized length (e.g. 70 mm) thelength of the wobble shaft necessarily is relatively long. By firstconverting the orbital motion of the motor to purely rotary motion, thewobble shaft may be driven by a displacement arm or member, whosediameter of orbital motion may be precisely predetermined to achieve thedesired output orbit at the brush head with a wobble shaft of shortestpracticable length.

In the modification of FIGS. 1-7, the arrangement of the mechanism toprovide orbital-to-rotary-to-orbital motion enables the workingmechanism to be sufficiently compacted axially that, in a manualappliance of appropriate size to be hand held, a reversing valve may beconveniently built into the appliance. This may be controlled by simpleside-to-side movement of the thumb, while the device is in use, suchthat the working stroke of the brush may be converted from downward toupward with great facility and speed.

It should be understood, of course, that the specific forms of theinvention herein illustrated and described are intended to berepresentative only, as certain changes may be made therein withoutdeparting from the clear teachings of the disclosure. Moreover, althoughthe features of the invention are illustrated in the embodiment of apower driven toothbrush, many of the mechanisms and featuresincorporated therein are applicable in other environments. Accordingly,reference should be made to the following appended claims in determiningthe full scope of the invention.

We claim:
 1. A powered toothbrush appliance or the like, whichcomprises(a) a housing, (b) a non-rotatable, orbitally movable wobbleshaft mounted for universal pivoting movement in said housing, (c) saidwobble shaft including a first end supporting a working element and asecond driven end, (d) orbital output drive means in said housingcomprising a fluid-powered, nutating action motor having an orbitallymoving output element, (e) means directly connecting the orbitallymoving output element of the nutating action motor to the driven end ofthe wobble shaft.
 2. A powered toothbrush according to claim 1, furthercharacterized by(a) yieldable means on said wobble shaft operative tourge said output element into an angular position.
 3. A poweredtoothbrush according to claim 2, further characterized by(a) said wobbleshaft having a recess at its driven end, (b) said yieldable meansincluding a bearing plunger slideably received in said recess, andspring means acting between said bearing plunger and the wobble shaft,(c) said bearing plunger being arranged to mechanically couple thedriven end of the wobble shaft to the output element and, (d) saidspring means urging said plunger toward said output element.
 4. Apowered toothbrush according to claim 2, further characterized by(a)flexible means connecting said wobble shaft to said housing andaccommodating limited axial movement of said wobble shaft, and (b) saidyieldable means comprising a spring means acting between said housingand said wobble shaft to urge said shaft toward said output element.